SAINT LOUIS -- The dates for the 2010 U.S. Championship have shifted. The tournament is now scheduled from May 13-25 at the Chess Club and Scholastic Center of Saint Louis. The U.S. Championship will have a larger prize fund than 2009 with more than $170,000 up for grabs.

The U.S. Championship was rescheduled to prevent overlapping with the World Championship match between Veselin Topalov and Viswanathan Anand in Bulgaria in order to ensure the highest quality of coverage.

The format in 2010 is also a bit different and promises a unique and exciting experience. The opening ceremony is scheduled for May 13, and rounds one through seven (Swiss paired) will take place May 14-20. The final three rounds, scheduled for May 22-24, will feature a round-robin quad format that is sure to lead to some thrilling games of fighting chess. A possible playoff may take place on May 25, along with a community day for the players and a closing ceremony featuring various awards and prizes.

The tournament will host 24 of the best players in the country. Nine of the 24 spots have already been filled, which leaves 15 invitations still to be determined.

The 24 invited players include:

• The defending U.S. Champion - GM Hikaru Nakamura

• The winner of the 2009 U.S. Senior Open Championship - GM Larry Christiansen

• The winner of the 2009 U.S. Junior Championship - GM Ray Robson

• The 2009 U.S. Women's Champion - IM Anna Zatonskih

• The top five qualifiers from the 2009 U.S. Open Championship - GM-elect Alex Lenderman, GMs Sergey Kudrin, Alex Yermolinsky, Dmitry Gurevich, and Jesse Kraai

• The winner of the 2010 ICC State Champion of Champions - TBD

• The top 10 U.S. players by rating of the United States Chess Federation - TBD

• Four wildcard spots - TBD

The Chess Club and Scholastic Center also hosted the 2009 U.S. Championship in May and the 2009 U.S. Women's Championship in October.

"It was our privilege to host the 2009 U.S. Championship, and we're honored to be chosen again," said Tony Rich, executive director of the Chess Club and Scholastic Center of Saint Louis.

The top 10 U.S. players will be determined by their ratings according to the February USCF rating supplement. The ICC State Champion of Champions will be determined through an online tournament that will pit state champions against one another. Stay tuned for updates, special event information and a complete prize-fund breakdown.